Why write your own FTP server?
So, I finally got fed up with all other FTP servers and wrote my own. Why would someone in their right mind do something like this 2014?
As a developer the answer to most such questions is usually; to scratch an itch. For a very long time I’ve looked for a really simple FTP server that just works, out of the box!
My alternatives on GNU/Linux distributions have been: several variants of the original MIT/Athena ftpd, ProFTPD, Pure-FTPd, and vstfptd. Most of them are too damn difficult to configure, have ugly configuration files or are plainly just too confusing. With one exception, vsftpd. I really like vsftpd! It’s got a simple and well documented configuration file (inline as comments) and always worked almost painlessly for me.
However, over the past couple of Ubuntu LTS installations it’s been starting to act up on me. Not allowing me to have a group-writable root directory, and not even an ability to disable that security feature.
It’s simple really. I’m a developer. I have colleagues. We share
servers at work. We bootstrap and upgrade our embedded devices using
TFTP/FTP. We have one directory, usually /srv/ftp, which is group
writable and all developers are members of that group. Anyone can
upload a file there and the file servers … would you know … are
supposed to serve that file, as TFTP or anonymous FTP.
Maybe I’m a fringe user? Maybe secured local area networks, or laptop to embedded device crossed-cables networks, are no longer the “fad”? Maybe a sane built-in default is no longer cool or hipster enough?
I don’t know anymore, and this time I was so fed up chasing around for answers to “How to setup your ‘favorite’ FTP Server”, that I just sat down and fixed it once and for all. I figured I’d otherwise be doing this waltz over and over again, just like I already have, for the next 10 years …
I trawled the net once more for good candidates, this time for adoption and holy cow sacrifices. I wanted a very simple base to start from, which I could cut up into pieces, iteratively refactor and improve upon until I was happy. That took a while.
I’m a big fan of both the Free Software and the Open Source cultures. (They are slightly different you know.) I routinely work on software with GNU GPL, MIT/X11, Apache, and ISC licenses, but for most of my own creations I usually lean towards the very permissive ISC license. Maybe because most of my hobby work these days are quick and dirty hacks I don’t really care enough about. It’s a question of both taste and appropriateness – like software patents, I don’t like them either, but for anything which I have a great investment in, or has a great threshold of originality, I’d use a more restrictive license to make sure the software is kept in the open.
Anyway, I read much code, discarded several projects that were too big, too unreadable code or simply didn’t feel right. I tested so many small “FTP” servers that turned out to be unusable homegrown variants or school projects. There’s a lot of code out there … I finally settled on FtpServer by Xu Wang as a base for my little project. I suspect it too is a school project, but this one actually worked, right off the bat!
I got so excited that I immediately started improving it, cleaning up the source code, reindenting it (KNF) and fixing small bugs here and there. It was a perfect fit! This is where I made my big mistake, which I hope will not eventually kill this project in the end – the FtpServer project did not have a license … so I filed a bug to the GitHub issue tracker, added the ISC license to my fork and continued hacking away. The changes I’ve made are so substantial that there isn’t much left of the original code, so uftpd should be safe. Yes, I named it uftpd, the micro ftp server – the no nonsense file transfer protocol daemon.
The whole hack took about three days and I’ve learned a lot during this time! It was fun, inspiring and gave me a lot of creative energy that I can use in other projects: at work as well as at home :)
See the uftpd project home for download links.